Air brake



Dec. 25, 1928. 1,696,665

c. R. BOWEN AIR BRAKE l Filed March 26, 1928 2 Sheets-Sheet l f 'Hf l 1' & K 36 e 36 44 3f awww@ 4Ca owev,

Patented Dec. 25, 1928.

UNITED STATES CARL R. BOWEN, OF WILMINGTON, CALIFORNIA.

AIR BRAKE.

Application led 'March 26, 1928. Serial No. 264,682.-

My invention relates to improvement-sin air brakes and particularly to that type 1n which the application and release of the brakes are normally dependent on the proper functioning of the well known triple valve, it being my purpose to provide in connection with such air brakes a novel means effective to assure the release of the brakes after applie-ation in the event the triple valve sticks or otherwise fails to properly function; with such means entirely under the control of the air pressure of the train line.

Furthermore, it is my purpose to provide a novel means or device of the type specified which will effectively operate for the purposes intended regardless of the maximum train line pressure employed in the air brake system with which such device may be associated. In other words my improved means or device is characterized by its ability to automatically adjust itself for ei'ective operation under varying maximum train line pressures.

More specifically my invention comprises a valve controlling the exhaust of air from the brake cylinder and improved means operatively responsive to train line pressure to move said valve to a position which willpermit the proper reduction of air pressure in the brake cylinder to eiect release of the brakes in the event the triple valve Jfails to properly function.

I will describe my invention in the best form known to me at present; but it will be understood that the same is susceptible to changes in form and proportion and to desirable additions with the exercise of only ordinary mechanical skill and without departing from the spirit thereof.

In the drawings chosen to illustrate my invention the scope whereof is set forth in the appended claims- Figure 1 is a view partly lin section and partly in elevation of a portion of a conve-ntional air brake system showing my invention incorporated therein;

Figure 2, a vertical section of my invention showing the parts in the posit-ion they would occupy when the dog operating plunger is in its lowermost position;

Figure 3, a view similar to Figure 2 showing the parts in the positions they Vwould occupy when the train line pressure is at predetermined maximum and the brakes released;

Figure 4, a section on the line 4-4 of Figure 2; o

Figure 5, a section on the line 5 5 of Figure 2;

Figure 6', a ure 2; f

Figure 7, a detail perspective view of one of the dog carriers; and Y Figure 8, a detail perspective view 'of one of the dogs. i

section on the line 6-6 of Fig- Referring to Figure l, A indicates a brake.

cylinder which is connected in a conventional manner with an auxiliary reservoir B. A triple valve C, when functioning properly, controls the delivery and exhaust of' compressed air` to and from the brake cylinder in the manner well known in this art. Connection of the triple valve with a train line D is effected by a piping E.

My invention is particularly shown vin movement of the valve 14 islimited by a proliection 17 carried bythe section 10. The' passage 15 which surrounds the bushing 16 is connected by piping 18 with the interior of the brake cylinder A as shown in Figure 1; while the interior ofthe section 10 is connected by a piping 19 with a retainer pipe 20, through which latterv compressed air is adapted to be exhausted from the brake cylinder under predetermined conditions to effect release of the brakes. The `lower end of the interior of the `section 11 is enlarged as at 21 and slidably mounted in said enlargement is a cylindrical bushing 22, upward sliding` movement of which is limited by the shoulder 23; while downward sliding movement thereof is limited by the upper end of the section 12. Secured within the bushing 22 by pins 24-24 are oppositely disposed semi-cyliny drical dog carriers 25-25. These carriers are p-rovided with Vmating longitudinal grooves 26-26 in which latter are mounted dogs 27-27 adapted to coact with the valve stem 18 in a manner that will hereinafter appear. The bushing 22 and dog carriers 25 are normally held in the position shown inFigure 2 by a spring 28 surrounding the valve stem 13 and reacting from a shoulder 29 embodied in the section 11. The lower end of the valve stem 13 terminates in a rectangular enlargement or head 30 which, during reciprocation of the valve, travels in recesses 3131 formed in each dog carrier- 25, such interengagement between the head 30 and dog carriers serving to maintain the valve stem, dog carrier and dogs in proper operative assembly as will be obvious. Immediately above the enlargement 30V the if'alve stem 13 is provided with a series of cireumscribing grooves 32 each ot which embodies an outwardly flared upper wall 33 and a lower wall 34 located in a plane at right angles to the axis of the valve stem 13.

Referring now to the construction and mounting of the dogs 27 it will be noted that each dog is provided with a transverse groove 35 opening through its inner face and that each of said grooves receives a` pivot pin 3G mounted in the related dog carrier 25 and extending across the recess 26. Each dog 27 is yieldingly held against its related pin 3G by a. spring 37 seated in an opening 33 in its related carrier 25. The lower ends ot the dogs 27 are enlarged as at 39 and said lower ends are constantly urged toward each other by springs 40-40 mounted in respective carriers 25. The upper end of each dog 27 terininates in a lateral extension 41 directed toward the valve stem 13 and the free endV of each extension is recessed as at 42 in confJormit-y with the upper walls 33 ot' the recessses 32. ln the arrangement shown the lateral extensions 41 are located just above the upper ends of the recesses 31-31 and are Y therefore always in position to engage the valve stem 13 above the. head 30 in the area of the grooves 32 as will be apparent.

Mounted for'reciprocation in the section 12 is a. plunger 43 which is adapted to be moved upwardly by train line pressure delivered against the lower end of said plunger by a piping 44 leading from the piping E. The upper end of the plunger is provided with a conical point 45 which coacts with the lower ends of the dogs during upward lmovement of said plunger to force said lower ends away from each other against the influence of the springs 40 and at the same time move the upper ends ot the dogs toward each other into engaging relation to the valve stem 13 as will be apparent.

The operation of my invention is as lollows. Assume the parts to be in the position shown Vin Fig. 2 in which status the plunger 43 is at its lowermost position and the pressure in the train line substantially exhausted. l'llhen the train line is charged to itsp-redetermined maximum the plunger 43 will be moved upwardly by the force of accumulat ing train'line pressure against the rear end thereof. As the plunger moves upwardly the point 45 will spread the lower' ends et the dogs 27 apart and at the same time the upper ends ot said dogsl will .engage in one of the g'ooves 32 of the valve stem 13 and against `struction heretofore described and said valve stem. After this operation takes place continued movement oi the plunger upwardly under the influence oi" accumulating train line pressure will cause the dog carriers 25, dogs 27 and bushing 22 to be elevated from the position shown in Fig. 2 to the position shown in Fig. 3 and this last named movement will result in the valve 14 being moved trom closed position to open position. ln other words, the parts will assume the position shown in Fig. 3. rlhe trainV line being new charged to its predetermined maximum assume that the brakes are applied by reducing the train line pressure. llllhen this reduction occurs the pressure behind the plunger 43 will be reduced and the spring 33 will return theplunger. dogs 27, plunger carriers 25 and bushing 22 downwardly until such parts Contact with the upper end of the section 12 and thus close valve 14 to properly retain the air pressure in the brake cylinder for brake application. Upon release et the brakes the train line pressure will build up and the valve 14 will again be moved to open position. Should the triple valve fail to properly function to .e'lliect such release oi' the brakes in the usual way, it will be apparent that the brake cylinder will be vented through the pipe 18, passage land'pipe 19 so as to assure the release of the brakes regardless of the failure of the triple valve to function. From the :foregoing it will be apparent that when the brakes are applied the valve 14 is closed and that when the brakes are released the valve`14 is open and that such open and closed positions of the valve are controlled entirely bythe train line pressure.

It will be further apparent that the conillustra-ted in Figures 2 and 3 will effectively operate to accomplish the desired purpose at all times regardless oit the predetermined maXimum train line pressure. Should the train line pressure be in excess et that required to produce the status of parts as shown in Fig. 3, it will be apparent that the dogs 27 can ride over the ared walls 33 of the grooves 32 and move up the stem of the valve 14 until the greater maximum pressure of the train line is balanced by the spring 28, the upper ends of the dogs 41 then engagl ing in a groove 32 above that in which they engage in the status shown in Fig. 3. When the device has thus vautomatically adjusted itself to the increased predetermined train line pressure the operationand result will be the same as that heretofore described.

1 claim:

1. The'combination with a brake cylinder and a train line. of a vent for the brake cylinder, a valve tor opening and closing said vent, means constantly tending to move said valve to a position to close the vent, and means operated by train line pressure to move said valve to a position to open the vent, said last named means being movable relatively to the valve in the direction of its valve opening movement and after said valve is in full open position to thereby adjust itself for correct valve operation under variable maximum train line pressures.

2. A brake cylinder venting device for air brakes comprising a casing having a passage therein adapted to form a portion of a brake cylinder vent, a valve in said casing movable to open and close said passage, means in said casing constantly tending` to move the valve to closed position, .and a gripping device ivithin the casing operable by train line pressure to grip said valve and then move the latter to open position.

3. A brake cylinder venting device for air brakes comprising a Casing having a passage therein adapted to form a portion of a brake cylindervent, a valve in said easing movable to open and close said passage, means in said casing constantly tending to move the valve to closed position, a gripping device Within the casing operable by train line pressure to gripsaid valve and then move the latter to open position, and means whereby said gripping device may be moved relatively to the valve While in gripping relation to the latter.

4. A brake cylinder venting device for air brakes comprising a casing having a passage therein adapted to form .a portion of a brake cylinder vent, a valve in said casing movable to open and close said passage, means in said casing constantly tending to move the valve to closed position, a pair of pivotally and bodily movable gripping dogs mounted in the casing, and means operable by train line pressure to pivot the dogs into gripping relation to the valve and then move said dogs bodily to thereby move the valve to open position.

5. A brake cylinder venting device for air brakes comprising a casing having a passage therein adapted to forma portion of a brake Cylinder vent, a valve in said casing movable to open and close said passage, means in said casing constantly tending to move the valve toY closed position, a pair of pivotally and bodily movable gripping dogs mounted in the casing, means operable by train line pressure to pivot the dogs into gripping relation to the valve and then move said dogs bodily to thereby move the valve to open position, and means whereby said dogs may move bodily relatively to the valve While in gripping relation to the valve and with the latter in its full open position. Y

In testimonyA whereof I'hereunto aiiix my signature.

CARL R. BOWEN. 

